<template>
  <div class="spec-preview">
    <img :src="skuImageList[index].imgUrl" />
    <div class="event" @mousemove="hander"></div>
    <div class="big" >
      <img :src="skuImageList[index].imgUrl" ref="big"/>
    </div>
    <div class="mask" ref="mask"></div>
  </div>
</template>

<script>
  export default {
    name: "Zoom",
    props:['skuImageList'],
    data() {
      return {
        index :0
      }
    },
    mounted() {
      this.$bus.$on('curimg',index=>this.index=index)
    },
    methods: {
      hander(event){
       let mask = this.$refs.mask
       let left= event.offsetX - mask.offsetWidth/2
       let top= event.offsetY - mask.offsetHeight/2

       if(left<0)left = 0
       if(left>mask.offsetWidth)left = mask.offsetWidth

        if(top<0)top = 0
       if(top>mask.offsetHeight)top = mask.offsetHeight

   
        mask.style.left = left + 'px'
        mask.style.top = top + 'px'
       
        let big =this.$refs.big
          big.style.left = -2 * left + 'px'
          big.style.top = -2 * top + 'px'
      }
        
         
    },
 

  }
</script>

<style lang="less">
  .spec-preview {
    position: relative;
    width: 400px;
    height: 400px;
    border: 1px solid #ccc;

    img {
      width: 100%;
      height: 100%;
    }

    .event {
      width: 100%;
      height: 100%;
      position: absolute;
      top: 0;
      left: 0;
      z-index: 998;
    }

    .mask {
      width: 50%;
      height: 50%;
      background-color: rgba(0, 255, 0, 0.3);
      position: absolute;
      left: 0;
      top: 0;
      display: none;
    }

    .big {
      width: 100%;
      height: 100%;
      position: absolute;
      top: -1px;
      left: 100%;
      border: 1px solid #aaa;
      overflow: hidden;
      z-index: 998;
      display: none;
      background: white;

      img {
        width: 200%;
        max-width: 200%;
        height: 200%;
        position: absolute;
        left: 0;
        top: 0;
      }
    }

    .event:hover~.mask,
    .event:hover~.big {
      display: block;
    }
  }
</style>